The long shot of life elsewhere

November 25, 2013
by Skip Derra

Recent research suggests that there may be as many as 40 billion habitable planets in our galaxy. A number that large has some scientists speculating that the universe might be teeming with life.

Before we eagerly set out to find our interstellar brethren, ASU cosmologist and author Paul Davies says we need to take a hard look at the odds of life elsewhere.

Thanks to Charles Darwin, we know a lot about how life evolved on Earth, but we know very little about how it first arose on this once sterile planet. Current thinking assumes there had to be the right chemicals and the right environmental conditions to set up a series of reactions that somehow led to the most basic of life forms.

According to Davies, the actual odds of the right chemical and environmental conditions coming together on a habitable planet at the right times to trigger an unlikely series of events are completely unknown because we don't know what those reactions and conditions were. The odds might indeed turn out to be favorable, as many scientists intuitively feel. But, on the other hand, they might equally well be very slim; indeed, less than, say, one in a trillion trillion.

In our present state of ignorance, we simply cannot say, Davies adds.

"Set against a number that big – and once you decide a series of unlikely accidents is behind the creation of life, you get enormous odds very easily – it is irrelevant whether the Milky Way contains 40 billion habitable planets or just a handful," he writes in "Are we alone in the Universe?" in the Nov. 19 New York Times. "Forty billion makes hardly a dent in a trillion trillion."

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10 comments

It is not so much we are alone in the universe, it is just that the likelihood of intelligent life evolving beyond the things it thinks are smart, like fracking and creating oceanic dead zones, for the made-up concept of money, are so small, that intelligent life in the universe exists for a virtual eyeblink, and the odds of those two eyes being open at the same time are remotely small.

And not so long ago, before we were able to detect any there were very serious astronomers who postulated that planets themselves are a unique phenomenon with our Sun quite possibly being a rather unique star in having them.

The recently admitted refusal of space agencies to probe the most likely places for life in our own system, because we cannot eliminate all risks of Earth germs hitching along 4 ride makes assuming so negatively just plain stupid.

We have yet to even honestly look in our own system!

While caution is always in order when making outlandish claims, I'd think the most outlandish claim would be one rooted in th notion we r so special and unique in the universe that the odds against life elsewhere is a trillion trillion to one.

That we don't know the exact requirements for life to take hold isn't the same as absolute ignorance or utter lack of evidence of what is likely.

When we finally achieve the level of tech know how to find life elsewhere we will find it.

Well we have looked havent we? And speculating on parameters enables us to narrow our search and waste less time

Yes, we have looked, but we haven't looked in the right way. As our understanding has grown over the past few decades, it has become clear that SETI didn't really have a chance to succeede. We are still two, maybe three generations of telescopes away from the sensitivity needed. That probably places it within the lifetimes of some of the people here, but not quite yet. Even a solid confirmation wouldn't convince some people though, and further confirmation would be problematic.

The abstract representation of value is essential for a civilization to develop. No civilization could exist without money

I think I agree, and that's pretty profound. Even if you look at hive insects, they seem to demonstrate abstract value of a sort. Ants, for example, will sacrifice self for eggs and the colony.

"Money acts as a standard measure and common denomination of trade. It is thus a basis for quoting and bargaining of prices. It is necessary for developing efficient accounting systems. But its most important usage is as a method for comparing the values of dissimilar objects."

-The need for money became obvious to the goatherder who needed to secure produce from the farmer who didn't need goatsmilk.

40 billion? A trillion trillion? Define conditions. When it is said the conditions on a planet are suitable for life to start it leaves me wondering how do you describe conditions. It may be freezing cold and snowing in one place and hot as hell and dry in another. Those are completely different conditions. There are potentially billions of different "conditions" on earth right now depending on the level of detail with which it is evaluated. There could be millions more tomorrow that are completely different. Given all the possibilities I'd say a trillion trillion is easy to reach and has been done many times over. Yes I know how many zeroes that is. Life only has to start in one place once for it to take over!

Then there's metallicity, variability, single vs. double star systems, place in the galaxy. There are actually (relatively speaking) not very many stars in our galaxy like ours taking into account all the possible variables.

Now, ours isn't the only kind of star life could evolve circling. Quite the contrary, orange dwarfs might even be more hospitable...but my POINT is that just looking at our star alone we fail the principle of mediocrity so using that principle as a basis for thinking life might be common is a non starter.

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